Fenders

ABSTRACT

A fender arrangement for a jetty, dockside, dolphin or the like comprising a fender mounted for load-absorbing movement towards the edge of the jetty against the action of normally unstrained elastomeric tension springs in the form of endless bands looped between mounting pedestals carried by the jetty and the fender. The fender may be slender driven piling or bodily carried and guided by the jetty. Tension springs of elastomeric material show specified advantages over compression and shear springs in jetty fenders.

United States Patent [151 3,695,046

Torr et al. 1 Oct. 3, 1972 [54] FENDERS 1,191,445 7/1916 Lowy ..114/219X[72] Inventors: Ralph E Ton. New Malden; 2,420,677 5/ 1947 Peterson..61/48 2,991,841 7/ 1961 Sampson et al ..182/1-39 Juncker ZeloNicolaisen, Crawley, b th ofEn and 3,464,214 9/1969 King ..61/48 g2,424,635 7/1947 Schwall ..61/48 [73] Assignee: Andre Rubber CompanyLimited, 3,379,020 4/1968 Krug ..61/48 X sma -Pes k vtbit o ,9551.England Primary Examiner-David J. Williamowsky Assistant Examiner-DavidH. Corbin [221 mm AttorneySughrue, Rothwell, Mion, Zinn & Macpeak [21]Appl. No.: 5,430

, [57] ABSTRACT [30] Foreign Application Priority Data A fenderarrangement for a jetty, dockside, dolphin or 2 69 the like comprising afender mounted for load-absorb- Jan. 23, Great Britain ..3,86 i g mo wathe g of the g st the action of normally unstrained elastomeric tension[52] US. Cl ..61/46, 61/48 springs in the form of endless bands loopedbetween [51] Int. Cl. ..E02b 3/22 mounting pedestals carried by thejetty and the fender Field of Sear h 114/219, 220, 230; The fender maybe slender driven piling or bodily car- 267/73, 153; 182/139 ried andguided by the jetty. Tension springs of elastomeric material showspecified advantages over [56] Re e Cited compression and shear springsin jetty fenders.

UNITED STATES PATENTS 646,553 4/1900 Holmes ..61/48 1,145,749 7/1915Claud ..l14/219 8 Claims, 8 Drawing Figures [Ll] I r I I I II I 11 OPATENTEU UT 3 I972 SHEET 3 UF 3 FENDERS BACKGROUND OF THE INVENTIONField of the Invention and absorb loads due to the arrival, departureand mooring of ships alongside the jetty.

SUMMARY OF THE INVENTION According to the invention in one aspect thereis provided a load absorbing arrangement comprising a fender adapted tobe arranged for movement towards and away from a generally rigidstructure to be protected, and elastomeric tension spring, first meansmounting a portion of said spring for movement with the fender, andsecond means mounting another portion of said spring, said second meansbeing adapted to be secured to a generally rigid structure to beprotected, whereby in use movement of the fender towards the structurecauses movement of said first and second means away from one another toextend the spring.

According to the invention in another aspect there is provided a fenderarrangement for a jetty or the like comprising a fender mounted formovement towards an edge of the jetty against the action of anelastomeric tension spring.

The arrangement is preferably such that the spring is substantiallyunstrained when the fender is in its unloaded condition.

In one application of the invention the generally rigid structure wouldbe a structure it is desired to protect from shock loadings due towaterborne vessels and as such the structure would generally be mountedto the bed of a stretch of fresh or sea water or to the shore or bankadjacent the water and extending into the water. Such structures includejetties, quays, piers, harbor walls, mooring dolphins, channel markers,and lighthouse and bridge foundations and will be referred to herein asjetties and the like. Fenders according to the invention might also havesome application on certain classes of waterborne vessels, such as tugsor' barges, in which case the rigid structure is the vessel.

In the application of the invention to jetties or the like, the fendermay comprise slender piling driven into the water bed adjacent thejetty, the cross-sectional dimensions of the piling being chosen suchthat the piling can flex at its upper end towards and away from thejetty according to the expected loading. Alternatively the fender may bearranged so that in use it is carried by the rigid structure in a mannerpermitting bodily movement of the fender towards and away from thestructure. In addition the fender is preferably carried so that itarticulate to a limited extent about an axis in the general plane of thefender. Preferably the fender is rotatable to a limited extent (up to oreven about two such axes, one axis being horizontal and the othervertical whereby the fender can accommodate itself to varying vesselside inclinations and to varying angles of orientation of the vesselslongitudinal axis.

The elastomeric tension springs could be single lengths, strands,cylinders or tubes of elastomeric material, suitably with enlarged andreinforced ends to facilitate securing to the spring mounting means. The

springs can alternatively be directly bonded to appropriate metal parts.Alternatively and preferably endless bands of elastomeric material maybe employed, the bands having any suitable cross-section and overallrelaxed shape. There may be a slight tendency to fretting of the bandswhere they pass over their mountings, e.g., shafts or shackle bolts, butthis can be alleviated by the use of suitable materials, and/orreinforcement, and/or shape, and/or lubrication.

It will be appreciated that an essential feature of the presentinvention involves the use of elastomeric material, such as natural orsynthetic rubber, which, at least during fendering, is in tensionbetween the fender and the rigid structure. The use of rubber incompression to absorb loads has been proposed in a number ofApplications, one reason being that it is generally thought in theengineering field that rubber in tension has a tendency to crack andfail under sustained stress. In arrangements according to the presentinvention the rubber springs can be arranged to be unstressed or onlylightly stressed while the fender is in its unloaded condition, therebysubstantially avoiding problems associated with sustained stress andalso giving the advantage of maximum average energy absorption per unitof rubber employed. Normally the duration of each fender operation wouldbe measurable in fractions of a minute. Finally a tension springarrangement is in itself stable and can readily be arranged so that thesprings can be strained to several times their static length duringfendering.

A plurality of springs would normally be provided between the fender anda structure. Springs arranged so that loading is applied in thedirection of the spring would exhibit stress/strain curves, according tothe elastomer employed, which would directly determine the fendercharacteristics, provided the springs are of equal length and pick-upload in unison. However, in particular applications the springs may beof different lengths and/or of different elastomers and/or be arrangedto pick up loads at different travel positions of the fender and/or bearranged in different inclinations, I

so that the fender characteristics can be modified as desired.

In summary two main advantages of elastomeric tension springs as opposedto other springs such as shear or compression springs in fenders arefirstly that a much greater energy input per unit volume can be obtainedand secondly that much larger strains at uniform stress are possible.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will nowbe described, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 is a vertical section through part of a jetty and a fenderarrangement according to the invention on line A--A of FIG. 2,

FIG. 2 is a section on line B-B of FIG. 1,

FIG. 3 is a perspective view of another embodiment of the invention,

FIGS. 4 and 5 are fragmentary views of part of the fender of FIG. 3,FIG. 4 being a section on line C--C of FIG. 5, and

FIGS. 6, 7 and 8 are a plan and respective side elevations of a furtherembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2there is shown a jetty having piling and an overhanging deck 11. Firstspaced mounting pedestals 12 are secured beneath the deck 11 and serveto support a shaft 13 parallel to and spaced beneath the deck edge. Theshaft may be withdrawn from the pedestals to facilitate assembly.Adjacent to andspaced from the jetty piling there is provided a shipfender in the form of slender driven fender piling, suitably of timber,one pile of which is shown at 14. Piles 14 are sufficiently slender tobow or flex towards the jetty under loading. At its upper end pile 14carries a pair of rearwardly extending spaced metal brackets 15 having astrengthening and guiding flange 16. The rearward ends of the bracketsserve as second mounting pedestals 17 to carry a second shaft 18arranged parallel to the first shaft 13. As shown in FIG. 2 the secondmounting pedestal 17 is guided laterally between adjacent firstpedestals 12. Endless rubber bands 19 loop over the two shafts, those inthe upper half of FIG. 2 being removed for clarity. The bands are ofsuch length as to be substantially unstressed when the fender is in itsunloaded condition.

In operation when a vessel brushes or rides against fender 14 the fender14 bows towards the jetty moving shaft 18 rearwardly away from fixedshaft 13. This causes the bands 19 to strain in tension to build up astress equal and opposite to the fender loading whereby to absorb thevessel loading. The travel deflection of the top of the fender 14 isshown by distance T in FIG.

Referring to FIG. 3 there is shown a fender in the form of a timberfaced framework 30 and a massive tubular cross spaced rearwardly of theframework, the cross having two opposed vertical arms 31 and two opposedhorizontal arms 32. The cross is removably mounted to the framework 30by suitable truss members 33. Four similar mounting and guidingpedestals 34 are secured to the seaward face of a jetty (not shown), onepedestal being associated with each of the four arms of the cross. Threepedestals have been removed from the figure for clarity.

The illustrated pedestal 34 comprises two similar braced right cornerassemblies 35, 36 spaced apart vertically back to back to define ahorizontal guideway 38 for rearward movement of the associated cross arm31 or 32. The remaining three pedestals are similar, though turnedthrough one, two and three right angles respectively to provideguideways for the four cross arms. The forward spaced ends of the twoassemblies 35, 36 carry a removable shaft 39 forward of and parallel tothe associated cross arm 31 or 32. A plurality of adjacent rubber bands40 are looped between each shaft 39 and its associated cross arm 31 or32.

It will be seen that the weight of the fender is to some extent borne bythe cross arms 32 travelling in guideways 38 and that the fender is tosome extent similarly laterally located by cross arms 31 travelling inthe vertical guideways (not shown). Buoya'ncy of the fender, dependingon the water level, would also bear some of the fender weight to preventit tilting forwardly, but preferably suitable auxiliary stops, rubberpads, buffers and/or chains or the like are provided loosely to restrainand stabilize the fender in its desired vertical position, as shown,when unloaded.

In operation distributed loading due to a vessel as shown by arrows 41would strain the bands 40 in tension, rearward motion of the fendertowards the jetty being guided by the four guideways 38. It will be seenthat the fender can also rotate to a limited extent (e.g., 10 to 20) ineither sense about both axes A and B lying in the axes of the cross arms31 and 32, whereby the fender facing can align itself with the vesselside the better to accommodate and distribute the vessel loading. Forcesparallel to the jetty caused by the ship rolling or dragging on thefender are transferred to the jetty by the cross arms 31 and 32 bearingagainst the sides of the appropriate guideways 38.

Referring to FIGS. 4 and 5 there is shown in more detail a fender springand spring mounting assembly, similar reference numerals being used forsimilar parts in FIG. 3 for convenience, though this illustratedassembly could have other fender applications than the arrangement ofFIG. 3. Basically the two spring mounting pedestals comprise a steelbracket forming part of and joining corner assemblies 35, 36 and secondsteel brackets 51 secured to trusses 33. Shaft 32 is removably carriedby brackets 51 and guided in guideway 38 formed as spaced elongate slotsin the two side plates 52 of bracket 50. A forked web 53 extends betweenside plates 52 for strength. The side plates 52 carry half roundelastomeric rubbing strips 52 at their forward end and side plates 55 ofbracket 51 similarly carry half round rubbing strips 56 at theirrearward end to reduce chaffing together of side plates 52 and 55 duringfendering.

Referring now to FIGS. 6, 7 and 8 there is shown a breasting dolphinrespectively in plan view and two mutually perpendicular sideelevations. In FIG. 8 part is removed and the view is in fact on lineB-B of FIG. 6. The dolphin comprises a substantially generally boxshaped framework 60 mounted on piling 61 and carrying a ship fender inthe form of a generally rectangular box 62, without lid or bottom,surrounding the dolphinframework 60 and suspended from the uppermostpart 63 of framework60 by two chains 64. The box 62 is preferably framedby members (not shown) extending through openings in framework 60 toenhance the structural strength of box 62. t

A plurality of sets of elastomeric tension springs extend between thefender and the dolphin framework 60. The springs include rows of bands65 and 66 which co-operate resiliently to oppose and absorb loadsexerted on the fender to the left and to the right in FIG. 8. The loadsexerted to the left on the right hand face of the fender would extendbands 65 into a state of tension. Bands 67 extend vertically between alower member of the fender and the dolphin and provide resilientopposition to vertical upward movement of the fender caused for exampleby swelling seawater. This prevents the chains becoming too slack andavoids extreme shock loading on the chains when the swell subsides.Bands 68 and 69 extend in two spaced horizontal parallel rows to absorbloading on the fender to the right in FIG. 7. Loading to the left inFIG. 7 is absorbed by four or more elastomeric buffers 70 mountedadjacent band rows 68 and 69 for compression between the fender and theframework 60 when the fender is moved to the left in FIG. 7.

It will be appreciated that the illustrated fender is constructedprimarily to absorb loading from the left in FIG. 7 (by bands 68 and 69)due to shipping buffing against this left hand face 71 of the fenderwhich is appropriately shaped. Longitudinal rubbing by a ship againstface 71 would be absorbed by bands 65 and 66, and vertical rubbing bybands 67 in co-operation with the weight of the fender opposed by chains64 and any buoyancy of the fender depending on the water level. All thebands co-operate to absorb the normal loading and fretting due to waveaction and other water movement loading which may effect the fender..

The two chains 64 diverge outwardly from their point of suspension asshown in FIG. 8. This arrangement in co-operation with bands 65 and 66assists in stabilizing the fender in its neutral position. The chains 64are also inclined in the same sense upwardly from their point ofsuspension on the fender, which lies substantially in the vertical planeincluding the center of gravity of the fender. This is shown in FIG. 7and it will be apparent that the chain tension and the weight of thefender give a resultant force urging the inner face of wall 72 of thefender firmly against the buffers 70, whereby to minimize frettingmovement of the fender due to wave action.

in this, as in the other described embodiments, the springs may bearranged between the fender and the rigid framework in a manner andpattern to suit the desired application and the expected direction ordirections of ship loading. Moreover more than two chains 64 may beemployed. It is preferable, particularly where more than two chains areused that the chains incorporate in their length or their mountings, oneor more flexible units whereby to reduce high stresses due to shockloadings.

We claim:

1. In a marine jetty fendering arrangement for use with vessels, a jettycomprising a generally rigid structure mounted to the sea bed and havinga generally horizontal forward edge above sea level;

a fender arrangement for protecting said jetty structure from any shockloadings due to impacts from vessels, said fender arrangement comprisinga ship fender having a generally vertical load receiving face, said faceextending substantially forwardly of and parallel to said jetty edge;

support means associated with said jetty, said support means carryingthe fender for movement of the fender relative to the jetty structure ina general direction perpendicular to said jetty edge, said fenderincluding a rearwardly extending portion extending rearwardly asubstantial distance behind said forward edge of the jetty;

a plurality of elastomeric tension spring means;

first mounting means connected to each said spring means, and

second mounting means connected to each said spring means, said firstmounting means being secured to said rearwardly extending portion ofsaid fender at a point more remote from said load receiving surface thansaid jetty edge, and said second mounting means being secured to saidjetty structure at a point between said jetty edge and said firstmounting means, said elastomeric tension springs comprising endlessbands of elastomeric material encircling said first and second mountingmeans, whereby movement of the ship fender towards the jetty edge causesmovement of said first mounting means rearwardly further away from saidsecond mounting means to strain elastomeric tension spring meanssubstantially purely in tension to absorb the energy of any shockloadings on said fender thereby protecting said jetty against theeffects of impact by vessels.

2. A jetty fendering arrangement according to claim 1, where saidelastomeric tension spring means includes loops of rubber materialconnecting said jetty and fender arrangement.

3. A jetty fendering arrangement according to claim 1, wherein saidsupport means includes a plurality of pairs of guide members, andwherein said rearwardly extending portion of said fender includes aplurality of arms, each arm having a first portion of its length beingguidingly received between a respective pair of said guide members, saidguide members defining and permitting generally horizontal movement ofsaid fender with respect to said jetty with said arm portions sliding insaid pairs of guide members, whereby said spring means return saidfender to a rest position so that said spring means are substantiallyunstrained in the absence of loading.

4. A marine jetty fendering arrangement according to claim 3, whereinsaid first mounting means comprises a second portion of the length ofeach of said plurality of fender arms, said second mounting meanscomprises spaced mounting pedestals secured to said jetty structure andshaft means extending between said pedestals.

5. A marine jetty fendering arrangement according to claim 4, whereinsaid fender arms comprise .a horizontal cross arm and a vertical crossarm centrally intersecting said horizontal arm, said horizontal crossarm being guided by two pairs of said guide members disposed adjacentopposite ends of said arm, and said vertical cross arm being guided bytwo pairs of said guide members disposed adjacent opposite ends of saidarm, whereby said fender is capable of rotation to a limited extent bothabout the horizontal axis defined by said horizontal cross arm and aboutthe vertical axis defined by said vertical cross arm, whereby the loadreceiving surface of said fender can align and accommodate itself to thevarying inclinations of the side of a vessel impinging on said fender.

6. A marine jetty fendering arrangement according to claim 5, whereinsaid fender is constructed of timber, the buoyancy of said fenderserving to bear a proportion of the weight of said fender.

7. In a marine jetty fendering arrangement for waterborne vessels, ajetty comprising a generally rigid structure mounted to the sea bed andhaving a generally horizontal forward edge above sea level;

a fender arrangement adapted to protect said jetty structure from anyshock loadings due to impact by waterborne vessels, said fenderarrangement comprising a row of driven piling driven generallyvertically into the sea bed a short distance in front of said jetty,said row being generally parallel to said jetty edge, said piles beingslender and adapted to flex towards and away from the edge of the jettywithout themselves offering much resistance to shock loading bywaterborne vessels;

a bracket secured to each said pile, said bracket extending rearwardly asubstantial distance behind said forward edge of the jetty;

a plurality of elastomeric tension springs;

first mounting means mounting a first portion of each said spring, and

second mounting means mounting a second portion of each said spring,said first mounting means being secured to the rearward end of saidrearwardly extending bracket, and said second mounting means beingsecured to said jetty structure at a point between said jetty edge andsaid first mounting means, said elastomeric tension springs comprisingendless bands of rubber material encircling said first and secondmounting means whereby in use flexing movement of the fender pilestowards the jetty edge causes movement of the first mounting meansrearwardly further away from said second mounting means to strain saidelastomeric tension springs substantially purely in tension to absorbthe energy of any shock loadings on said fender thereby protecting saidjetty against the effect of impact by waterborne vessels.

8. A marine jetty fendering arrangement according to claim 7, whereinsaid slender piles are driven into the sea bed at such a distance infront of the jetty that when the piles are in a neutral unflexedcondition in the absence of loading then the elastomeric tension springsare in a substantially unstrained condition.

1. In a marine jetty fendering arrangement for use with vessels, a jettycomprising a generally rigid structure mounted to the sea bed and havinga generally horizontal forward edge above sea level; a fenderarrangement for protecting said jetty structure from any shock loadingsdue to impacts from vessels, said fender arrangement comprising a shipfender having a generally vertical load receiving face, said faceextending substantially forwardly of and parallel to said jetty edge;support means associated with said jetty, said support means carryingthe fender for movement of the fender relative to the jetty structure ina general direction perpendicular to said jetty edge, said fenderincluding a rearwardly extending portion extending rearwardly asubstantial distance behind said forward edge of the jetty; a pluralityof elastomeric tension spring means; first mounting means connected toeach said spring means, and second mounting means connected to each saidspring means, said first mounting means being secured to said rearwardlyextending portion of said fender at a point more remote from said loadreceiving surface than said jetty edge, and said second mounting meansbeing secured to said jetty structure at a point between said jetty edgeand said first mounting means, said elastomeric tension springscomprising endless bands of elastomeric material encircling said firstand second mounting means, whereby movement of the ship fender towardsthe jetty edge causes movement of said first mounting means rearwardlyfurther away from said second mounting means to strain elastomerictension spring means substantially purely in tension to absorb theenergy of any shock loadings on said fender thereby protecting saidjetty against the effects of impact by vessels.
 2. A jetty fenderingarrangement according to claim 1, where said elastomeric tension springmeans includes loops of rubber material connecting said jetty and fenderarrangement.
 3. A jetty fendering arrangement according to claim 1,wherein said support means includes a plurality of pairs of guidemembers, and wherein said rearwardly extending portion of said fenderincludes a plurality of arms, each arm having a first portion of itslength being guidingly received between a respective pair of said guidemembers, said guide members defining and permitting generally horizontalmovement of said fender with respect to said jetty with said armportions sliding in said pairs of guide members, whereby said springmeans return said fender to a rest position so that said spring meansare substantially unstrained in the absence of loading.
 4. A marinejetty fendering arrangement according to claim 3, wherein said firstmounting means comprises a second portion of the length of each of saidplurality of fender arms, said second mounting means comprises spacedmounting pedestals secured to said jetty structure and shaft meansextending between said pedestals.
 5. A marine jetty fenderingarrangement according to claim 4, wherein said fender arms comprise ahorizontal cross arm and a vertical cross arm centrally intersectingsaid horizontal arm, said horizontal cross arm being guided by two pairsof said guide members disposed adjacent opposite ends of said arm, andsaid vertical cross arm being guided by two pairs of said guide membersdisposed adjacent opposite ends of said arm, whereby said fender iscapable of rotation to a limited extent both about the horizontal axisdefined by said horizontal cross arm and about the vertical axis definedby said vertical cross arm, whereby the load receiving surface of saidfender can align and accommodate itself to the varying inclinations ofthe side of a vessel impinging on said fendeR.
 6. A marine jettyfendering arrangement according to claim 5, wherein said fender isconstructed of timber, the buoyancy of said fender serving to bear aproportion of the weight of said fender.
 7. In a marine jetty fenderingarrangement for waterborne vessels, a jetty comprising a generally rigidstructure mounted to the sea bed and having a generally horizontalforward edge above sea level; a fender arrangement adapted to protectsaid jetty structure from any shock loadings due to impact by waterbornevessels, said fender arrangement comprising a row of driven pilingdriven generally vertically into the sea bed a short distance in frontof said jetty, said row being generally parallel to said jetty edge,said piles being slender and adapted to flex towards and away from theedge of the jetty without themselves offering much resistance to shockloading by waterborne vessels; a bracket secured to each said pile, saidbracket extending rearwardly a substantial distance behind said forwardedge of the jetty; a plurality of elastomeric tension springs; firstmounting means mounting a first portion of each said spring, and secondmounting means mounting a second portion of each said spring, said firstmounting means being secured to the rearward end of said rearwardlyextending bracket, and said second mounting means being secured to saidjetty structure at a point between said jetty edge and said firstmounting means, said elastomeric tension springs comprising endlessbands of rubber material encircling said first and second mounting meanswhereby in use flexing movement of the fender piles towards the jettyedge causes movement of the first mounting means rearwardly further awayfrom said second mounting means to strain said elastomeric tensionsprings substantially purely in tension to absorb the energy of anyshock loadings on said fender thereby protecting said jetty against theeffect of impact by waterborne vessels.
 8. A marine jetty fenderingarrangement according to claim 7, wherein said slender piles are driveninto the sea bed at such a distance in front of the jetty that when thepiles are in a neutral unflexed condition in the absence of loading thenthe elastomeric tension springs are in a substantially unstrainedcondition.